So maybe your biology classes was just boring and your only joy was the painful death of little animals on the altar of science while you dissect them?
You know what is way more cooler? How about exploring the oceans with your own submarine? If you are ready to build your own, you are not alone: you can check Personals Submersibles Organization.
OK, maybe a little smaller, if you build it in your backyard.
If it seems too risky, or you prefer your armchair instead of small, cold, dark places, here is the OpenROV program for you! They even have a Kickstarter page!